chordates incude all of the following exept:a)cephalochordata b)Urochordata c)hemichordata d)none of the above
Answers
Explanation:
Urochordates or tunicates are marine organisms. These are filter-feeding animals. When the larva undergoes metamorphosis, the notochord in the tail and nerve cord degenerates. This is called retrogressive metamorphosis. There is a loss of advanced features while the development of larvae to adult.
The cephalochordates or lancelets have a long body. The body tapers or is pointed at both ends with a large notochord, that extends from tip to tip and is present throughout life.
Branchiostoma is one of the few living genera of lancelets or cephalochordates. It is not a hemichordate. These are snake-like organisms. There is dorsal nerve cord. They are close relatives of vertebrates.
Agnatha is a superclass of jawless fish in the phylum Chordata and subphylum Vertebrata. The group consists both present (living) cyclostomes and extinct conodonts and ostracoderms.